title: Statistical approaches to assessing single and multiple outcome measures in dry eye therapy and diagnosis.
abstract: Dry eye is a multifactorial disease which would require a broad spectrum of test measures in the monitoring of its treatment and diagnosis. However, studies have typically reported improvements in individual measures with treatment. Alternative approaches involve multiple, combined outcomes being assessed by different statistical analyses. In order to assess the effect of various statistical approaches to the use of single and combined test measures in dry eye, this review reanalyzed measures from two previous studies (osmolarity, evaporation, tear turnover rate, and lipid film quality). These analyses assessed the measures as single variables within groups, pre- and post-intervention with a lubricant supplement, by creating combinations of these variables and by validating these combinations with the combined sample of data from all groups of dry eye subjects. The effectiveness of single measures and combinations in diagnosis of dry eye was also considered.
authors.affiliation: Vision Sciences, Glasgow Caledonian University, Glasgow, United Kingdom. Electronic address: A.Tomlinson@gcu.ac.uk.
authors.forename: Alan
authors.initials: A
authors.lastname: Tomlinson
authors.forename: Mario
authors.initials: M
authors.lastname: Hair
authors.forename: Angus
authors.initials: A
authors.lastname: McFadyen
mesh_terms: D003627:Data Interpretation, Statistical; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D010043:Outcome and Process Assessment, Health Care / Q000379:methods*; D013666:Tears / Q000502:physiology*
keywords: ANCOVA; ANOVA; Analysis of covariance; Analysis of variance; EVAP; Evaporation rate; HPMC; Hydroxypropyl methylcellulose; KMO; Kaiser-Meyer-Olkin (measure of sampling adequacy); Lipid film quality; OSM; Osmolarity; TFI; TTR; Tear turnover rate; dry eye; outcome measures; statistical analysis; tear physiology